1 /* 2 * 8253/8254 interval timer emulation 3 * 4 * Copyright (c) 2003-2004 Fabrice Bellard 5 * Copyright (c) 2006 Intel Corporation 6 * Copyright (c) 2007 Keir Fraser, XenSource Inc 7 * Copyright (c) 2008 Intel Corporation 8 * Copyright 2009 Red Hat, Inc. and/or its affiliates. 9 * 10 * Permission is hereby granted, free of charge, to any person obtaining a copy 11 * of this software and associated documentation files (the "Software"), to deal 12 * in the Software without restriction, including without limitation the rights 13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 14 * copies of the Software, and to permit persons to whom the Software is 15 * furnished to do so, subject to the following conditions: 16 * 17 * The above copyright notice and this permission notice shall be included in 18 * all copies or substantial portions of the Software. 19 * 20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 26 * THE SOFTWARE. 27 * 28 * Authors: 29 * Sheng Yang <sheng.yang@intel.com> 30 * Based on QEMU and Xen. 31 */ 32 33 #define pr_fmt(fmt) "pit: " fmt 34 35 #include <linux/kvm_host.h> 36 #include <linux/slab.h> 37 38 #include "irq.h" 39 #include "i8254.h" 40 #include "x86.h" 41 42 #ifndef CONFIG_X86_64 43 #define mod_64(x, y) ((x) - (y) * div64_u64(x, y)) 44 #else 45 #define mod_64(x, y) ((x) % (y)) 46 #endif 47 48 #define RW_STATE_LSB 1 49 #define RW_STATE_MSB 2 50 #define RW_STATE_WORD0 3 51 #define RW_STATE_WORD1 4 52 53 /* Compute with 96 bit intermediate result: (a*b)/c */ 54 static u64 muldiv64(u64 a, u32 b, u32 c) 55 { 56 union { 57 u64 ll; 58 struct { 59 u32 low, high; 60 } l; 61 } u, res; 62 u64 rl, rh; 63 64 u.ll = a; 65 rl = (u64)u.l.low * (u64)b; 66 rh = (u64)u.l.high * (u64)b; 67 rh += (rl >> 32); 68 res.l.high = div64_u64(rh, c); 69 res.l.low = div64_u64(((mod_64(rh, c) << 32) + (rl & 0xffffffff)), c); 70 return res.ll; 71 } 72 73 static void pit_set_gate(struct kvm *kvm, int channel, u32 val) 74 { 75 struct kvm_kpit_channel_state *c = 76 &kvm->arch.vpit->pit_state.channels[channel]; 77 78 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); 79 80 switch (c->mode) { 81 default: 82 case 0: 83 case 4: 84 /* XXX: just disable/enable counting */ 85 break; 86 case 1: 87 case 2: 88 case 3: 89 case 5: 90 /* Restart counting on rising edge. */ 91 if (c->gate < val) 92 c->count_load_time = ktime_get(); 93 break; 94 } 95 96 c->gate = val; 97 } 98 99 static int pit_get_gate(struct kvm *kvm, int channel) 100 { 101 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); 102 103 return kvm->arch.vpit->pit_state.channels[channel].gate; 104 } 105 106 static s64 __kpit_elapsed(struct kvm *kvm) 107 { 108 s64 elapsed; 109 ktime_t remaining; 110 struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state; 111 112 if (!ps->period) 113 return 0; 114 115 /* 116 * The Counter does not stop when it reaches zero. In 117 * Modes 0, 1, 4, and 5 the Counter ``wraps around'' to 118 * the highest count, either FFFF hex for binary counting 119 * or 9999 for BCD counting, and continues counting. 120 * Modes 2 and 3 are periodic; the Counter reloads 121 * itself with the initial count and continues counting 122 * from there. 123 */ 124 remaining = hrtimer_get_remaining(&ps->timer); 125 elapsed = ps->period - ktime_to_ns(remaining); 126 127 return elapsed; 128 } 129 130 static s64 kpit_elapsed(struct kvm *kvm, struct kvm_kpit_channel_state *c, 131 int channel) 132 { 133 if (channel == 0) 134 return __kpit_elapsed(kvm); 135 136 return ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time)); 137 } 138 139 static int pit_get_count(struct kvm *kvm, int channel) 140 { 141 struct kvm_kpit_channel_state *c = 142 &kvm->arch.vpit->pit_state.channels[channel]; 143 s64 d, t; 144 int counter; 145 146 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); 147 148 t = kpit_elapsed(kvm, c, channel); 149 d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC); 150 151 switch (c->mode) { 152 case 0: 153 case 1: 154 case 4: 155 case 5: 156 counter = (c->count - d) & 0xffff; 157 break; 158 case 3: 159 /* XXX: may be incorrect for odd counts */ 160 counter = c->count - (mod_64((2 * d), c->count)); 161 break; 162 default: 163 counter = c->count - mod_64(d, c->count); 164 break; 165 } 166 return counter; 167 } 168 169 static int pit_get_out(struct kvm *kvm, int channel) 170 { 171 struct kvm_kpit_channel_state *c = 172 &kvm->arch.vpit->pit_state.channels[channel]; 173 s64 d, t; 174 int out; 175 176 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); 177 178 t = kpit_elapsed(kvm, c, channel); 179 d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC); 180 181 switch (c->mode) { 182 default: 183 case 0: 184 out = (d >= c->count); 185 break; 186 case 1: 187 out = (d < c->count); 188 break; 189 case 2: 190 out = ((mod_64(d, c->count) == 0) && (d != 0)); 191 break; 192 case 3: 193 out = (mod_64(d, c->count) < ((c->count + 1) >> 1)); 194 break; 195 case 4: 196 case 5: 197 out = (d == c->count); 198 break; 199 } 200 201 return out; 202 } 203 204 static void pit_latch_count(struct kvm *kvm, int channel) 205 { 206 struct kvm_kpit_channel_state *c = 207 &kvm->arch.vpit->pit_state.channels[channel]; 208 209 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); 210 211 if (!c->count_latched) { 212 c->latched_count = pit_get_count(kvm, channel); 213 c->count_latched = c->rw_mode; 214 } 215 } 216 217 static void pit_latch_status(struct kvm *kvm, int channel) 218 { 219 struct kvm_kpit_channel_state *c = 220 &kvm->arch.vpit->pit_state.channels[channel]; 221 222 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); 223 224 if (!c->status_latched) { 225 /* TODO: Return NULL COUNT (bit 6). */ 226 c->status = ((pit_get_out(kvm, channel) << 7) | 227 (c->rw_mode << 4) | 228 (c->mode << 1) | 229 c->bcd); 230 c->status_latched = 1; 231 } 232 } 233 234 static void kvm_pit_ack_irq(struct kvm_irq_ack_notifier *kian) 235 { 236 struct kvm_kpit_state *ps = container_of(kian, struct kvm_kpit_state, 237 irq_ack_notifier); 238 int value; 239 240 spin_lock(&ps->inject_lock); 241 value = atomic_dec_return(&ps->pending); 242 if (value < 0) 243 /* spurious acks can be generated if, for example, the 244 * PIC is being reset. Handle it gracefully here 245 */ 246 atomic_inc(&ps->pending); 247 else if (value > 0) 248 /* in this case, we had multiple outstanding pit interrupts 249 * that we needed to inject. Reinject 250 */ 251 queue_kthread_work(&ps->pit->worker, &ps->pit->expired); 252 ps->irq_ack = 1; 253 spin_unlock(&ps->inject_lock); 254 } 255 256 void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu) 257 { 258 struct kvm_pit *pit = vcpu->kvm->arch.vpit; 259 struct hrtimer *timer; 260 261 if (!kvm_vcpu_is_bsp(vcpu) || !pit) 262 return; 263 264 timer = &pit->pit_state.timer; 265 if (hrtimer_cancel(timer)) 266 hrtimer_start_expires(timer, HRTIMER_MODE_ABS); 267 } 268 269 static void destroy_pit_timer(struct kvm_pit *pit) 270 { 271 hrtimer_cancel(&pit->pit_state.timer); 272 flush_kthread_work(&pit->expired); 273 } 274 275 static void pit_do_work(struct kthread_work *work) 276 { 277 struct kvm_pit *pit = container_of(work, struct kvm_pit, expired); 278 struct kvm *kvm = pit->kvm; 279 struct kvm_vcpu *vcpu; 280 int i; 281 struct kvm_kpit_state *ps = &pit->pit_state; 282 int inject = 0; 283 284 /* Try to inject pending interrupts when 285 * last one has been acked. 286 */ 287 spin_lock(&ps->inject_lock); 288 if (ps->irq_ack) { 289 ps->irq_ack = 0; 290 inject = 1; 291 } 292 spin_unlock(&ps->inject_lock); 293 if (inject) { 294 kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1, false); 295 kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0, false); 296 297 /* 298 * Provides NMI watchdog support via Virtual Wire mode. 299 * The route is: PIT -> PIC -> LVT0 in NMI mode. 300 * 301 * Note: Our Virtual Wire implementation is simplified, only 302 * propagating PIT interrupts to all VCPUs when they have set 303 * LVT0 to NMI delivery. Other PIC interrupts are just sent to 304 * VCPU0, and only if its LVT0 is in EXTINT mode. 305 */ 306 if (kvm->arch.vapics_in_nmi_mode > 0) 307 kvm_for_each_vcpu(i, vcpu, kvm) 308 kvm_apic_nmi_wd_deliver(vcpu); 309 } 310 } 311 312 static enum hrtimer_restart pit_timer_fn(struct hrtimer *data) 313 { 314 struct kvm_kpit_state *ps = container_of(data, struct kvm_kpit_state, timer); 315 struct kvm_pit *pt = ps->kvm->arch.vpit; 316 317 if (ps->reinject || !atomic_read(&ps->pending)) { 318 atomic_inc(&ps->pending); 319 queue_kthread_work(&pt->worker, &pt->expired); 320 } 321 322 if (ps->is_periodic) { 323 hrtimer_add_expires_ns(&ps->timer, ps->period); 324 return HRTIMER_RESTART; 325 } else 326 return HRTIMER_NORESTART; 327 } 328 329 static void create_pit_timer(struct kvm *kvm, u32 val, int is_period) 330 { 331 struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state; 332 s64 interval; 333 334 if (!irqchip_in_kernel(kvm) || ps->flags & KVM_PIT_FLAGS_HPET_LEGACY) 335 return; 336 337 interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ); 338 339 pr_debug("create pit timer, interval is %llu nsec\n", interval); 340 341 /* TODO The new value only affected after the retriggered */ 342 hrtimer_cancel(&ps->timer); 343 flush_kthread_work(&ps->pit->expired); 344 ps->period = interval; 345 ps->is_periodic = is_period; 346 347 ps->timer.function = pit_timer_fn; 348 ps->kvm = ps->pit->kvm; 349 350 atomic_set(&ps->pending, 0); 351 ps->irq_ack = 1; 352 353 /* 354 * Do not allow the guest to program periodic timers with small 355 * interval, since the hrtimers are not throttled by the host 356 * scheduler. 357 */ 358 if (ps->is_periodic) { 359 s64 min_period = min_timer_period_us * 1000LL; 360 361 if (ps->period < min_period) { 362 pr_info_ratelimited( 363 "kvm: requested %lld ns " 364 "i8254 timer period limited to %lld ns\n", 365 ps->period, min_period); 366 ps->period = min_period; 367 } 368 } 369 370 hrtimer_start(&ps->timer, ktime_add_ns(ktime_get(), interval), 371 HRTIMER_MODE_ABS); 372 } 373 374 static void pit_load_count(struct kvm *kvm, int channel, u32 val) 375 { 376 struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state; 377 378 WARN_ON(!mutex_is_locked(&ps->lock)); 379 380 pr_debug("load_count val is %d, channel is %d\n", val, channel); 381 382 /* 383 * The largest possible initial count is 0; this is equivalent 384 * to 216 for binary counting and 104 for BCD counting. 385 */ 386 if (val == 0) 387 val = 0x10000; 388 389 ps->channels[channel].count = val; 390 391 if (channel != 0) { 392 ps->channels[channel].count_load_time = ktime_get(); 393 return; 394 } 395 396 /* Two types of timer 397 * mode 1 is one shot, mode 2 is period, otherwise del timer */ 398 switch (ps->channels[0].mode) { 399 case 0: 400 case 1: 401 /* FIXME: enhance mode 4 precision */ 402 case 4: 403 create_pit_timer(kvm, val, 0); 404 break; 405 case 2: 406 case 3: 407 create_pit_timer(kvm, val, 1); 408 break; 409 default: 410 destroy_pit_timer(kvm->arch.vpit); 411 } 412 } 413 414 void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val, int hpet_legacy_start) 415 { 416 u8 saved_mode; 417 if (hpet_legacy_start) { 418 /* save existing mode for later reenablement */ 419 saved_mode = kvm->arch.vpit->pit_state.channels[0].mode; 420 kvm->arch.vpit->pit_state.channels[0].mode = 0xff; /* disable timer */ 421 pit_load_count(kvm, channel, val); 422 kvm->arch.vpit->pit_state.channels[0].mode = saved_mode; 423 } else { 424 pit_load_count(kvm, channel, val); 425 } 426 } 427 428 static inline struct kvm_pit *dev_to_pit(struct kvm_io_device *dev) 429 { 430 return container_of(dev, struct kvm_pit, dev); 431 } 432 433 static inline struct kvm_pit *speaker_to_pit(struct kvm_io_device *dev) 434 { 435 return container_of(dev, struct kvm_pit, speaker_dev); 436 } 437 438 static inline int pit_in_range(gpa_t addr) 439 { 440 return ((addr >= KVM_PIT_BASE_ADDRESS) && 441 (addr < KVM_PIT_BASE_ADDRESS + KVM_PIT_MEM_LENGTH)); 442 } 443 444 static int pit_ioport_write(struct kvm_io_device *this, 445 gpa_t addr, int len, const void *data) 446 { 447 struct kvm_pit *pit = dev_to_pit(this); 448 struct kvm_kpit_state *pit_state = &pit->pit_state; 449 struct kvm *kvm = pit->kvm; 450 int channel, access; 451 struct kvm_kpit_channel_state *s; 452 u32 val = *(u32 *) data; 453 if (!pit_in_range(addr)) 454 return -EOPNOTSUPP; 455 456 val &= 0xff; 457 addr &= KVM_PIT_CHANNEL_MASK; 458 459 mutex_lock(&pit_state->lock); 460 461 if (val != 0) 462 pr_debug("write addr is 0x%x, len is %d, val is 0x%x\n", 463 (unsigned int)addr, len, val); 464 465 if (addr == 3) { 466 channel = val >> 6; 467 if (channel == 3) { 468 /* Read-Back Command. */ 469 for (channel = 0; channel < 3; channel++) { 470 s = &pit_state->channels[channel]; 471 if (val & (2 << channel)) { 472 if (!(val & 0x20)) 473 pit_latch_count(kvm, channel); 474 if (!(val & 0x10)) 475 pit_latch_status(kvm, channel); 476 } 477 } 478 } else { 479 /* Select Counter <channel>. */ 480 s = &pit_state->channels[channel]; 481 access = (val >> 4) & KVM_PIT_CHANNEL_MASK; 482 if (access == 0) { 483 pit_latch_count(kvm, channel); 484 } else { 485 s->rw_mode = access; 486 s->read_state = access; 487 s->write_state = access; 488 s->mode = (val >> 1) & 7; 489 if (s->mode > 5) 490 s->mode -= 4; 491 s->bcd = val & 1; 492 } 493 } 494 } else { 495 /* Write Count. */ 496 s = &pit_state->channels[addr]; 497 switch (s->write_state) { 498 default: 499 case RW_STATE_LSB: 500 pit_load_count(kvm, addr, val); 501 break; 502 case RW_STATE_MSB: 503 pit_load_count(kvm, addr, val << 8); 504 break; 505 case RW_STATE_WORD0: 506 s->write_latch = val; 507 s->write_state = RW_STATE_WORD1; 508 break; 509 case RW_STATE_WORD1: 510 pit_load_count(kvm, addr, s->write_latch | (val << 8)); 511 s->write_state = RW_STATE_WORD0; 512 break; 513 } 514 } 515 516 mutex_unlock(&pit_state->lock); 517 return 0; 518 } 519 520 static int pit_ioport_read(struct kvm_io_device *this, 521 gpa_t addr, int len, void *data) 522 { 523 struct kvm_pit *pit = dev_to_pit(this); 524 struct kvm_kpit_state *pit_state = &pit->pit_state; 525 struct kvm *kvm = pit->kvm; 526 int ret, count; 527 struct kvm_kpit_channel_state *s; 528 if (!pit_in_range(addr)) 529 return -EOPNOTSUPP; 530 531 addr &= KVM_PIT_CHANNEL_MASK; 532 if (addr == 3) 533 return 0; 534 535 s = &pit_state->channels[addr]; 536 537 mutex_lock(&pit_state->lock); 538 539 if (s->status_latched) { 540 s->status_latched = 0; 541 ret = s->status; 542 } else if (s->count_latched) { 543 switch (s->count_latched) { 544 default: 545 case RW_STATE_LSB: 546 ret = s->latched_count & 0xff; 547 s->count_latched = 0; 548 break; 549 case RW_STATE_MSB: 550 ret = s->latched_count >> 8; 551 s->count_latched = 0; 552 break; 553 case RW_STATE_WORD0: 554 ret = s->latched_count & 0xff; 555 s->count_latched = RW_STATE_MSB; 556 break; 557 } 558 } else { 559 switch (s->read_state) { 560 default: 561 case RW_STATE_LSB: 562 count = pit_get_count(kvm, addr); 563 ret = count & 0xff; 564 break; 565 case RW_STATE_MSB: 566 count = pit_get_count(kvm, addr); 567 ret = (count >> 8) & 0xff; 568 break; 569 case RW_STATE_WORD0: 570 count = pit_get_count(kvm, addr); 571 ret = count & 0xff; 572 s->read_state = RW_STATE_WORD1; 573 break; 574 case RW_STATE_WORD1: 575 count = pit_get_count(kvm, addr); 576 ret = (count >> 8) & 0xff; 577 s->read_state = RW_STATE_WORD0; 578 break; 579 } 580 } 581 582 if (len > sizeof(ret)) 583 len = sizeof(ret); 584 memcpy(data, (char *)&ret, len); 585 586 mutex_unlock(&pit_state->lock); 587 return 0; 588 } 589 590 static int speaker_ioport_write(struct kvm_io_device *this, 591 gpa_t addr, int len, const void *data) 592 { 593 struct kvm_pit *pit = speaker_to_pit(this); 594 struct kvm_kpit_state *pit_state = &pit->pit_state; 595 struct kvm *kvm = pit->kvm; 596 u32 val = *(u32 *) data; 597 if (addr != KVM_SPEAKER_BASE_ADDRESS) 598 return -EOPNOTSUPP; 599 600 mutex_lock(&pit_state->lock); 601 pit_state->speaker_data_on = (val >> 1) & 1; 602 pit_set_gate(kvm, 2, val & 1); 603 mutex_unlock(&pit_state->lock); 604 return 0; 605 } 606 607 static int speaker_ioport_read(struct kvm_io_device *this, 608 gpa_t addr, int len, void *data) 609 { 610 struct kvm_pit *pit = speaker_to_pit(this); 611 struct kvm_kpit_state *pit_state = &pit->pit_state; 612 struct kvm *kvm = pit->kvm; 613 unsigned int refresh_clock; 614 int ret; 615 if (addr != KVM_SPEAKER_BASE_ADDRESS) 616 return -EOPNOTSUPP; 617 618 /* Refresh clock toggles at about 15us. We approximate as 2^14ns. */ 619 refresh_clock = ((unsigned int)ktime_to_ns(ktime_get()) >> 14) & 1; 620 621 mutex_lock(&pit_state->lock); 622 ret = ((pit_state->speaker_data_on << 1) | pit_get_gate(kvm, 2) | 623 (pit_get_out(kvm, 2) << 5) | (refresh_clock << 4)); 624 if (len > sizeof(ret)) 625 len = sizeof(ret); 626 memcpy(data, (char *)&ret, len); 627 mutex_unlock(&pit_state->lock); 628 return 0; 629 } 630 631 void kvm_pit_reset(struct kvm_pit *pit) 632 { 633 int i; 634 struct kvm_kpit_channel_state *c; 635 636 mutex_lock(&pit->pit_state.lock); 637 pit->pit_state.flags = 0; 638 for (i = 0; i < 3; i++) { 639 c = &pit->pit_state.channels[i]; 640 c->mode = 0xff; 641 c->gate = (i != 2); 642 pit_load_count(pit->kvm, i, 0); 643 } 644 mutex_unlock(&pit->pit_state.lock); 645 646 atomic_set(&pit->pit_state.pending, 0); 647 pit->pit_state.irq_ack = 1; 648 } 649 650 static void pit_mask_notifer(struct kvm_irq_mask_notifier *kimn, bool mask) 651 { 652 struct kvm_pit *pit = container_of(kimn, struct kvm_pit, mask_notifier); 653 654 if (!mask) { 655 atomic_set(&pit->pit_state.pending, 0); 656 pit->pit_state.irq_ack = 1; 657 } 658 } 659 660 static const struct kvm_io_device_ops pit_dev_ops = { 661 .read = pit_ioport_read, 662 .write = pit_ioport_write, 663 }; 664 665 static const struct kvm_io_device_ops speaker_dev_ops = { 666 .read = speaker_ioport_read, 667 .write = speaker_ioport_write, 668 }; 669 670 /* Caller must hold slots_lock */ 671 struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags) 672 { 673 struct kvm_pit *pit; 674 struct kvm_kpit_state *pit_state; 675 struct pid *pid; 676 pid_t pid_nr; 677 int ret; 678 679 pit = kzalloc(sizeof(struct kvm_pit), GFP_KERNEL); 680 if (!pit) 681 return NULL; 682 683 pit->irq_source_id = kvm_request_irq_source_id(kvm); 684 if (pit->irq_source_id < 0) { 685 kfree(pit); 686 return NULL; 687 } 688 689 mutex_init(&pit->pit_state.lock); 690 mutex_lock(&pit->pit_state.lock); 691 spin_lock_init(&pit->pit_state.inject_lock); 692 693 pid = get_pid(task_tgid(current)); 694 pid_nr = pid_vnr(pid); 695 put_pid(pid); 696 697 init_kthread_worker(&pit->worker); 698 pit->worker_task = kthread_run(kthread_worker_fn, &pit->worker, 699 "kvm-pit/%d", pid_nr); 700 if (IS_ERR(pit->worker_task)) { 701 mutex_unlock(&pit->pit_state.lock); 702 kvm_free_irq_source_id(kvm, pit->irq_source_id); 703 kfree(pit); 704 return NULL; 705 } 706 init_kthread_work(&pit->expired, pit_do_work); 707 708 kvm->arch.vpit = pit; 709 pit->kvm = kvm; 710 711 pit_state = &pit->pit_state; 712 pit_state->pit = pit; 713 hrtimer_init(&pit_state->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); 714 pit_state->irq_ack_notifier.gsi = 0; 715 pit_state->irq_ack_notifier.irq_acked = kvm_pit_ack_irq; 716 kvm_register_irq_ack_notifier(kvm, &pit_state->irq_ack_notifier); 717 pit_state->reinject = true; 718 mutex_unlock(&pit->pit_state.lock); 719 720 kvm_pit_reset(pit); 721 722 pit->mask_notifier.func = pit_mask_notifer; 723 kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier); 724 725 kvm_iodevice_init(&pit->dev, &pit_dev_ops); 726 ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, KVM_PIT_BASE_ADDRESS, 727 KVM_PIT_MEM_LENGTH, &pit->dev); 728 if (ret < 0) 729 goto fail; 730 731 if (flags & KVM_PIT_SPEAKER_DUMMY) { 732 kvm_iodevice_init(&pit->speaker_dev, &speaker_dev_ops); 733 ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, 734 KVM_SPEAKER_BASE_ADDRESS, 4, 735 &pit->speaker_dev); 736 if (ret < 0) 737 goto fail_unregister; 738 } 739 740 return pit; 741 742 fail_unregister: 743 kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &pit->dev); 744 745 fail: 746 kvm_unregister_irq_mask_notifier(kvm, 0, &pit->mask_notifier); 747 kvm_unregister_irq_ack_notifier(kvm, &pit_state->irq_ack_notifier); 748 kvm_free_irq_source_id(kvm, pit->irq_source_id); 749 kthread_stop(pit->worker_task); 750 kfree(pit); 751 return NULL; 752 } 753 754 void kvm_free_pit(struct kvm *kvm) 755 { 756 struct hrtimer *timer; 757 758 if (kvm->arch.vpit) { 759 kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &kvm->arch.vpit->dev); 760 kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, 761 &kvm->arch.vpit->speaker_dev); 762 kvm_unregister_irq_mask_notifier(kvm, 0, 763 &kvm->arch.vpit->mask_notifier); 764 kvm_unregister_irq_ack_notifier(kvm, 765 &kvm->arch.vpit->pit_state.irq_ack_notifier); 766 mutex_lock(&kvm->arch.vpit->pit_state.lock); 767 timer = &kvm->arch.vpit->pit_state.timer; 768 hrtimer_cancel(timer); 769 flush_kthread_work(&kvm->arch.vpit->expired); 770 kthread_stop(kvm->arch.vpit->worker_task); 771 kvm_free_irq_source_id(kvm, kvm->arch.vpit->irq_source_id); 772 mutex_unlock(&kvm->arch.vpit->pit_state.lock); 773 kfree(kvm->arch.vpit); 774 } 775 } 776